Apical Flap Repositioning vs. Mucosa Excision With Free Gingival Grafts for Peri-Implant Keratinized Mucosa Augmentation (FGGIF)

Multicenter Randomized Clinical Trial Comparing Apical Flap Repositioning Versus Vestibular Mucosa Excision Associated With Free Gingival Grafts for Peri-Implant Keratinized Mucosa Augmentation

The goal of this clinical trial is to learn which surgical technique works better to increase the amount of firm gum tissue (called keratinized mucosa) around dental implants in adults.

The main question it aims to answer is:

-Does repositioning the gum flap upward with stitches lead to a greater gain in firm gum tissue width at 6 months compared to simply removing the extra gum tissue, when both techniques are combined with a free gum graft?

Researchers will compare two techniques used during the second stage of implant surgery to see which one produces a greater gain in firm gum tissue around the implant.

Participants will:

• Receive a free gum graft (a small piece of tissue taken from the roof of the mouth) placed around their dental implant during a routine surgical visit
• Be randomly assigned to one of the two surgical techniques
• Have digital scans of their mouth taken at 5 timepoints over 6 months
• Complete a pain diary and answer questions about their experience during the first week after surgery
• Attend follow-up visits at 6 weeks, 3 months, and 6 months after surgery

Study Overview

• Status: Not yet recruiting
• Conditions: Dental Implants; Keratinized Mucosa Deficiency; Peri-implant Soft Tissue
• Intervention / Treatment: Procedure: Free gingival graft with apical flap repositioning; Procedure: Free gingival graft with vestibular mucosa excision

Detailed Description

This superiority multicenter randomized clinical trial is coordinated by the Universitat de Barcelona (UB) and includes the Universidad Complutense de Madrid (UCM) as a collaborating center.

Participant selection Adults with osseointegrated implants in the posterior maxilla or mandible presenting keratinized mucosa width of 2 mm or less and/or vestibular depth less than 4 mm will be screened for eligibility. Participants must be in periodontal and peri-implant health and have a plaque index of 15% or less.

Randomization Eligible participants will be randomly assigned (1:1) to one of two treatment groups using an Interactive Web Response System (IWRS) provided by Sealed Envelope Ltd. Randomization will take place intraoperatively, once the partial-thickness mucosal flap has been prepared.

Interventions

Group 1 (Control): Free gingival graft with apical repositioning and suturing of the vestibular mucosal flap to the periosteum Group 2 (Experimental): Free gingival graft with excision of the vestibular mucous tissue

Outcome assessment Soft tissue changes will be assessed at 5 timepoints (T0, Tim, T6w, T3m, T6m) using intraoral scans (TRIOS 3®, 3Shape) analyzed with Geomagic Control X® software through three-dimensional digital superimposition. Clinical measurements will also be performed using a calibrated periodontal probe and a customized thermoplastic stent to standardize the measurement point across visits.

Participants will complete a pain diary during the first 7 postoperative days recording pain intensity (100 mm visual analogue scale), analgesic consumption, and days with limited activity.

Sample size A total of 46 participants (23 per group) are required, accounting for a minimum clinically relevant difference of 1 mm in KTW gain, a standard deviation of 1.3 mm, 80% statistical power, 5% significance level, an intraclass correlation coefficient of 0.30 for multiple implants per patient, and a 15% dropout rate.

Statistical analysis The primary outcome will be analyzed in the intention-to-treat population using a generalized linear mixed model (GLMM), with patient as a random effect, adjusted for baseline KTW and study center.

• Study Type: Interventional
• Enrollment (Estimated): 46
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Octavi Camps-Font, DDS MS PhD; Phone Number: +34 934 024 269; Email: ocamps@ub.edu
• Study Contact Backup: Name: Prof. Dr.; Email: ocamps@ub.edu

Study Locations

• Spain
  • Barcelona
    • Barcelona, Barcelona, Spain, 08907
      • Hospital Odontològic Universitat de Barcelona, L'Hospitalet de Llobregat,
      • Contact: Octavi Camps Font DDS MS PhD; Phone Number: +34 934 024 269; Email: ocamps@ub.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Men or women aged 18 years or older who voluntarily agree to sign the informed consent form before any study-related procedure is performed.
• Single or multiple edentulous spaces (≤3 units) located in the posterior maxilla or mandible, presenting osseointegrated implants in first-stage surgery with a -healing period of more than 8 weeks.
• ASA classification I or II.
• Periodontal and peri-implant health.
• O'Leary plaque index ≤15%.
• Keratinized mucosa width ≤2 mm and/or vestibular depth <4 mm at at least one site.
• Commitment to attend all follow-up visits over 6 months.

Exclusion Criteria:

• Systemic diseases that may interfere with performing FGG (free gingival graft), including but not limited to: poorly controlled diabetes mellitus (HbA1c > 8% or per clinical judgment), immunodeficiencies or immunosuppressive treatment, uncontrolled hematological diseases or coagulation disorders, anticoagulant or antiplatelet treatment that cannot be adjusted according to standard clinical practice, active neoplasms under treatment, severe renal or hepatic insufficiency, decompensated cardiovascular diseases, and any other medical condition that, in the investigator's judgment, could compromise participant safety or proper tissue healing.
• Any contraindication to oral surgical procedures.
• Periodontal and peri-implant health as defined by the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions.
• Patients who smoke tobacco or equivalent products, as well as former smokers with an abstinence period ≤12 months.
• History of substance abuse (drugs or alcohol) or any other factor (e.g., severe psychiatric illness) that, in the investigator's opinion, could interfere with the patient's ability to cooperate and comply with the study.
• Patients who have participated in a clinical trial within the last 30 days.
• Pregnant or breastfeeding women.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Apical Flap Repositioning; Free gingival graft with apical repositioning and suturing of the vestibular mucosal flap to the periosteum during second-stage implant surgery.	Procedure: Free gingival graft with apical flap repositioning; Autologous free gingival graft harvested from the palate and placed at the recipient site. The vestibular mucosal flap is repositioned apically and sutured to the periosteum during second-stage implant surgery.
Experimental: Vestibular Mucosa Excision; Free gingival graft with excision of the vestibular mucous tissue during second-stage implant surgery.	Procedure: Free gingival graft with vestibular mucosa excision; Autologous free gingival graft harvested from the palate and placed at the recipient site. The vestibular mucous tissue is excised during second-stage implant surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Peri-implant keratinized tissue width (KTW) gain	Absolute change in KTW, measured digitally as the linear distance between the mucosal margin and the mucogingival junction on the vestibular aspect of the implant, using Geomagic Control X® software on intraoral scan models (TRIOS 3®, 3Shape).	Baseline (T0) to 6 months (T6m)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinical gain in peri-implant keratinized tissue width (KTW)	Absolute change in KTW, measured clinically with a calibrated periodontal probe using a customized thermoplastic stent.	Baseline (T0) to 6 months (T6m)
Change in graft height	Change in graft height, measured in millimeters (mm), between immediate postoperative and 6 months, assessed by 3D digital superimposition.	Immediate postoperative (Tim), 6 weeks (T6w), 3 months (T3m), 6 months (T6m)
Change in graft width	Change in graft width, measured in millimeters (mm), between immediate postoperative and 6 months, assessed by 3D digital superimposition.	Immediate postoperative (Tim), 6 weeks (T6w), 3 months (T3m), 6 months (T6m)
Graft area contraction	Percentage of graft area reduction between immediate postoperative and 6 months, assessed by 3D digital superimposition.	Immediate postoperative (Tim) to 6 months (T6m)
Change in graft volume	Change in graft volume, measured in cubic millimeters (mm³), between immediate postoperative and 6 months, assessed by 3D digital superimposition.	Immediate postoperative (Tim), 6 weeks (T6w), 3 months (T3m), 6 months (T6m)
Vestibular depth	Change in vestibular depth from baseline to 6 months, assessed both digitally and clinically.	Baseline (T0) to 6 months (T6m)
Surgical time	Time in minutes from anesthesia administration to placement of the last suture.	Intraoperative (Tim)
Adverse events	Incidence and nature of postoperative adverse events related to the free gingival graft procedure.	Immediate postoperative (Tim) to 6 months (T6m)
Clinician-perceived surgical difficulty	Degree of surgical difficulty perceived by the clinician at the end of the procedure, evaluated using a 100 mm visual analogue scale (0 = no difficulty, 100 = maximum imaginable difficulty).	Intraoperative (Tim)
Postoperative pain	Pain intensity recorded at the end of the procedure and at 2, 6, 12 and 24 hours, and daily for 7 days, using a 100 mm visual analogue scale (0 = no pain, 100 = worst imaginable pain).	Up to 7 days postoperat
Analgesic consumption	Number of doses of ibuprofen 600 mg and paracetamol 1 g consumed during the first 7 postoperative days.	Up to 7 days postoperative
Patient global satisfaction	Overall satisfaction with the intervention evaluated at 7 days postoperative using a 100 mm visual analogue scale (0 = completely dissatisfied, 100 = completely satisfied).	7 days postoperative
Days with limitation of daily activity	Number of days with total or partial limitation of usual daily activity during the first 7 postoperative days.	Up to 7 days postoperative

Collaborators and Investigators

• Sponsor: University of Barcelona
• Collaborators: Universidad Complutense de Madrid
• Investigators: Study Director: Octavi Camps Font, University of Barcelona

Publications and helpful links

Helpful Links

• Hospital Odontològic Universitat de Barcelona

Study record dates

Study Major Dates

• Study Start (Estimated): September 30, 2026
• Primary Completion (Estimated): September 30, 2028
• Study Completion (Estimated): March 30, 2029

Study Registration Dates

• First Submitted: August 3, 2026
• First Submitted That Met QC Criteria: August 15, 2026
• First Posted (Actual): August 19, 2026

Study Record Updates

• Last Update Posted (Actual): August 19, 2026
• Last Update Submitted That Met QC Criteria: August 15, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: Keratinized mucosa; Free gingival graft; Intraoral scanner; Soft tissue augmentation; Peri-implant mucosa; Second-stage implant surgery; Apical flap repositioning; Vestibuloplasty
• Other Study ID Numbers: 26/2026

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No